#include <stdio.h>
#define RATE1 0.12589
#define RATE2 0.17901
#define RATE3 0.20971
#define BREAK1 360.0
#define BREAK2 680.0
#define BASE1 (RATE1 * BREAK1)
#define BASE2 (BASE1 + (RATE2 * (BREAK1 - BREAK2)))
int main(void)
{
    double kwh;
    double bill;
    printf("Please enter the kwh used.\n");
    scanf("%lf", &kwh);
    if(kwh <= BREAK1)
        bill = BREAK1 * kwh;
    else if(kwh <= BREAK2)
        bill = BASE1 + (RATE2 * (kwh - BREAK1));
    else
        bill = BASE2 + (RATE3 * (kwh - BREAK2));
    printf("The charge for %.1f kwh is $%1.2f.\n", kwh, bill);
    getchar();
    getchar();
    return 0;
}
